Russia transported missiles for the S-300 complex through the Bosphorus, despite Türkiye's ban
It should be recalled that Türkiye has closed the Bosphorus and Dardanelles straits to Russian warships, but merchant ships can pass through.
The Russian cargo ship Sparta II sailed through the strait and arrived at a Russian port where there is a large naval base near the Kerch Bridge.
Presumably, the ship sailed from Tartus to Syria, where the S-300 was assembled at the pier.